Art of treating liquid materials



Nov. 24, 1925- G. D. HARRIS NG LIQUID MATERIALS Patent-ed Nov. 24, 1925.

interno Siri/;ii'risI P A T E NT FI C E.

Gonnon Don HARI-ns,, or Isrirr, NnWiAYonI, Assreno'nl,, BY Mvnsnn nssrenmnn'rs; To rntn mnnsrmnz; erwynn conronnrron. or senior-enn, ooimnc'rrour. A oona new or Tnnn'rmer LIQUID MATERIALS.

Application filed motel-'23; 1920.

To ml] ili/iamy fil* may concern:

Be it known that I, Gouuon Don* Hiiuus, :i citizen. of 'the United fltates, residing: at lip, county of Sull'oll', ang State of- Non' ir have invented a. certui'nncw and useful riirt of Treuting Liquid Materials, of lwhii'fh the following` ;i speciliczition-' invention pertains to the zirt of liquid materials, and is directed, inore puitic'ulerly, to in ``ns for concentratinfr :nid postcurizing: such liquids as milk, l gh it Will lie unders-tood:that said ine. i f r fictcd to the treatment of milk alone, for the reason that the principle or ;he invention or the :ipperof'us 'to he hereinufter described may he utilized in the erfqiorationor desiccetion of' other liquid or seni-limiirl materials, such :is eggs. blood,

.ln the ort of tr'V ting materials Which are subject to rapid deteriorition underntinospheric and other influences, such as milk and inore wspecizilly Whole milk, with a View to the i 'inato production of e, dry powder,

such us i :l'

11, :ire conrci'trited and pasteuro lieiug preferred to flow the liquid crit under coi'ditions Which trz'nquiilize such flow so -us to involve mii'iunun physical d' urhziure of the constituents of said inateri-zl and concurrentlyf with such flow to heat said material to :i temperature Which effects post/eurizrtion, and filso to expose' suid material to the eyaporntingnotion of :i drying atmosphere Which cireu'lutes into contact with the material in a, manner to e3:- chiinge heiit for moisture, as :i result of Which the aqueous contents of the fluid mu- -`fil is emporiited and the residue of such imiteriil is concentrzitet, the resulting prodsei-aai No. 419,053.

susceptihle of suhsequen't treatment for the I production of dry powder;

ln a preferred forin of apparatus, I employ a, plirality of inclined surfices, such. :is pans, over Which the liquid material is free to flow by gravity and upon Which surfaces said liquidneterizilis distributed in a relatively thin fihn. The rate of fiow of the liquid materialupon the surfaces o f the pons controlled. by the angle of- .inclinationof each pen; but as the speed of the n'niterial reduced When flowing overthc succe'ssive pns clue 'to zi' progressirelconcentriition which the liquid material under- ,g'oes by the'ev'aporetion ofthe aqueous content ther'ein, ithefcomes desirihle to position the second, third and successive'pans at increusingly greater' :inglesfof inclination, in order that said fluid undergoing concentration progressively Willitra'y'elfhyi'grayity at the desired speed upon the several pains.

tloopereting with the inclined fiovy pains are 'bullies positioned in' approximately perzillel relation' to` said pains' and forming' therewith flow channels through`Which circulates' :i dryingv atmosphere' adapted for coi'n'uct withfithe vlilm off-'liquid material, the flowof the drying atmosphere being in rem se direction; to the vflow ofthe liquid ini;- te-'l. Said dryingatmosphere is usually prcheated to e temperature suited to the particular material to be evap'orated, and when treatingnilk, the temperature such that the desired exchange of heat for moisture takes place ond'at thel same time the liquid material (milk) 'is heated to the toinpernture required for pestelirizngthe milk.y The exchange of heat formoisture under ordinaryr evnporating conditions reduces the temperature ofthe drying` agent, but this tendency to temperature reduction is overcome by the provision voflie-nting coils and heftles Withinthe flow channels anelogous in some respects to the system of air heating during circulation disclos'ed in theftlnited States patent to'lVi-ight, 1,251,817 of Deceniher 25, 1917;

In i the Operation of conccntrit :nid

ili

pasteurizing such fluid materials as milk, it is desirable that the flow ofthe milk in a thin 'lm over the pans and the flow from pan to another of the series shall talte place with the least physical disturbance or agitation of the eonstituents of the milk. These ends are attained in the first instance by the angle of inclination given to the pans; in the icond instance by the provision of spill *s at the delivery end of each pan, a'd ie third instance by a splash guard iate the delivery end of one pan ie receiving end of t-he next pan in the 'ie several elements operating to and maintain a tranquil flow of the ri al over the pans and from one the other while at the same time 1" occupy such relation to the `flow -..atthe drying atmos'here free over the pans and through the -uevs for the re'jguired contact with the or semi-fluid material. Sher functions and advantages of the tion will appear from the following tion taken in connection with the drawings, wherein 2-- lfigure l is a vertical section, partlyT in clevation, through the apparatus for drying liquid materials in accordance with this invention.

Figure 2 is plan View on an enlarged scale of the delivery end portion of one of the flow pans illustrating the channels adapted to produce spill-ways for the flew of material, and

Figure 3 is an end view of one of the pans looking at the spill-ways shown in Figure 2.

lVit-hin a casing or housing A is a plurality of flow pans, five being shown and designated by the numerals l, 2, 3,. a and 5, although it will be understood that the number of flow pans is not i'naterial,` and, further, that said number of pans may be incr ted or dcereased according to the lengih of time required to evaporate the aqueous contents of the liquid material.

llooperating with the flow pans and extendin' longitudinally within the housing r ng is a series of battles or partitions 3, 'T. 8 and S), the batlles or partitions 6 and nding from one end wall of the housard the other end thereof, and being tioned below the fiow pans 1 and 3 whereas the battles or partiand 5,) extend from the opposite 'all of the housing nearly to the first d (nid and said battles or partitions i' and i) :clng arranged below the flow pans 1d -iirespectively. lt, will be understood 1 the hal'lles or partitions (3,.7, 8 and 9 ue with the flow pans l, 2, 3 and -i'l to produce flow channels B, C, D, extending logitudinally within the g or casing, one end of each fiow t i on i cn d channel opening into a corresponding end of the next fiow channel so that the drying atmosphere is directed in a circuitous path within the housing. The series of pans extend within the flow channels, in order to expose the film of liquid material to the direct action of the drying atmosphere which circulates within said flow channels.

In this invention it is essential that each flow pan be inclined within its respective flow channel, but the angle of inclination of the the pans varies. The flow pan l extending within flow channel B is inclined at' such an angle that the liquid material is free to flow over the surface of the pan at a rate of speed controlled in a large measure by the angle of inclination of the pan, and during the exposure of the film upon the first flow pan l to the action of the drying atmosphere some of the aqueous content of the liquid material is evaporatcd, as a result of which the liquid material on the flow pan l is concentrated to a certain degree.

The flow pan 2 is positioned below the flow pan l and is inclined in a reverse direction to the inclination of said pan l, the angle of inclination of the flow pan 2 bcing somewhat greater than the angle of inclination of flow pan l. The delivery end of flow pan l overhangs the receiving end of the next flow pan 2, and the liquid material partly concentrated on flow pan l is free to flow upon the receiving end of pan 2, the flowing material being ditl'used over the surface of pan 2 and flowing toward the lower end of the pan at a rate which is governed by the partial concentration of the liquid material and the angle of inclination of said pan 2.

In like manner the next fiow pan Z- is positioned below pan 2 and inclined in the opposite direction to the inclination of pan 2, the receiving end of pan 3 extending beyond the delivery end of p'a'i 2 in order that the liquid material may tlow from pan 2 upon the flow pan 3.

Similarly, flow pan ft is positioned below pan 3 and is inclined in an opposite direction thereto, but the angle of inclination of flow pan 4 is greater than the angle of pan 3, the receiving end of pan .4. extending beyond the delivery end of pan 3. Pans 2 and 4; are inclined in the same general direction, but the angle of inclination of pan t is greater than the angle of inclii'iation of pans 2 and Furthermorc, pan 5 is below pan. -t and is inclined in an opposite direction to the inclination of pan l, and at a greater angle than said pan et, the receiving end of pan 5 being below the delivery end of pan ll.

As shown in Figure 1 the receiving end of the first pan (i) extends beyond the lll Ill

part thereo and adjacent to said deliv housin .l iu order that the liquid mai' in the reuired volume and at the tcu'perati may ho fed or suppli-.ri ;3. suitahle means directly to pan l. il. feei'l means for the liquid material is shown as a chute G connected with a tank G' Within Which is a heating coil g yvhereby the liquid material is adapted to he i eated to ihr temperature necessaryY to carry on the pasteurization of said liquid material. lt Vwill he under tood, however. that any desired ineans for prehcating;` the liquid material. and feeding` said liquid niet ..'ial to the rccciving' endof said flor; pan may he suhstituted for the feeding and l eatinm .ineau,--; illustrated diagrannnatically in lif'p re l.

The delivery end of the final. flow pan (53) extends beyond the housing at the lower ei'y end of the final pan is a receiving tank lil, the latter being provided with a suitable air vent 72. Wherehy the semi-liquid material fron the .final flow pan (5) is discharged Within the storage tani; H until it isdesired to subject the said material to further treatment in a manner to ultimately produce a dry powder.

According to this invention the liquid material is free to flow by gravity over the surfaces of the successive pans and at a speed Which, While assuring' a `;gravity flow, will avoid an undue physical disturhzuice of the constituents composinv` the material.. In order to tra-nquilize the 4now of the wid L Vmaterial When delivered fron'i one end of one pan to the correspo'ding' end of the `pan .next helow it, I find it desirahle to provide mal' rial passes through the spill-ways in rcla 'ily narrow strean's.

Positioned intermediate the delivery end of each pau and the receiving end of the pan next helouv it is a menher J serving' the function of a splash guard, upon Which the liquid material flowing in streams from the spill-Ways of one pan is deposited so that the splash guard conducts the liquid material to the pan next helow in a manner to tranquilize the flovv of the liquid material. The splash guard is preferably curved in order that the liquid material may flow With the .mininu'n'i of disturhance of the constitutents of the material, .and these splash guards are spaccd with respect to the tWo paus so that the drying atmosphere Will circulate 'freely from one flow channel into the next flow channel, the splash guard offering' the minimum of resistance or obstruction to the circulation of the drying atmosphere.

Positioned Within each flow channel is a heater l shown in the d''avvi s as acoil of pipe to Which is supplied hy sutahle means a heating agent such as steam, Water, or other heating agent. rl`he heating` coil extends Within the flow channel lonpgitudinally thereof, and said heating coil occupies a suhstantially parallel relation to thesurface of the flow pan extending Within the flow channel. The heating coil is spaced relatively to the Slow pan With Which it if; ciated, and with this coil cooperati transverse hati i, f I. The hal'tles are in series within each floxv chenn el transversely thereto, and

transversely also to the planeo'f the heating circulating Within said channel `is detlected from a straight path over the flow paincerf tain of the haflles acting to divert the drying atmosphere toward the surface of the pan and the film thereon, whereas other bullies diver-t the drying atmosphere with respect to the heznting coil, as airesult of Which the course of the drying atmosphere is so changed that in its flow over the pan the air coo'ies into contact with the film of material and with the heating` coil. The coils are of such capacity that they radiate the l'ieat required to maintain the drying atmosphere required at a desired temperature, notivithstandingI the exchange of heat for moisture, and said heaters act also lto heat the lihn of liquid material upon the flovv pans so as to maintain constant the liquid material at the tenunerature required to effect, ]'asteiu'ization.

rfhe drying; atmosphere is prcheated to the desired ternperatin'e and hloivu at the desired speed and volume into the housing' ji, the inlet m 'for the drying; atmosphere hei ill; adjacent the delivery end of the last flovv pun of the series, Figure l, whereas the outlet for thel drying' atmosphere is at the upper corner of the housing, said .outlet heingr in the form of a stack or uptake n.

The operation is as follows: 'l`he blower is set into operation for forcing' the drying atincuqihere through. the inlet and above the delivery end of the final flow pan (5), and liquid material is lnfeheated in the tank' ;H to the desired ten'iperature, the material flowingy through the chute G upon the receiving end of the first flow pan 'l. The liquid is distrilimted or difl'used over the surface of the flow pan l. in the form of a thin film and flows by gravi'y over said surface owing to the inclination of the first pan, the liquid being divided into Streams through the spill-ways I' and flowing thence upon the splash guard J, by which the liquid is distributed to the receiving` end of flow pan 2. The liquid flows successively from one pan to the next, the material being` diffused or distrilmted over each pan in th form of a film, and during the perio-:l of the flow of the liquid material over the saccessiye pans, the drying; atnmsphere is blown through the channels, the direction of the circulation of the drying atmosphere being contrary to the flow of the liquid material over the surfaces of the pans. :Che circulation of the drying; atmosphere in each channel is diverte-:l by the baflles li with respect to the plane of the pan and the heating,` coil, the drying' atmosphere being` directed into contact with the film of material upon the pan and into contact also with 'the heating` coil. The flow of the drying;` atmosphere over the material exchanges heat for moisture, thus erai ioratiing` the aqueous content of the material and heating,` the film of material to the temperature necessary for effect-ing pasteurization, it beingI important when drying certain liquhl materials to maintain constant temperature of the material. The continued 'flow of inatori al in film like condition over the successire flow pans, and the continued circulation of the drying atmosphere into contact with the material operates by the evaporation of moisture to concentrate the liquid material while maintaining the same at the desired temperature for pasteurization, as a result of which the liquid material is so concentrated that it a'ttains a thick consistency by the time the material floi from the delivery end of the final flow pan into the tank H, whence the liquid material may at a subsequent period be subjected to additional treatment in order to ultimately produce a dry powder.

Having thus described the invention, what l claim as new and desire to secure by lietters Patent is:

l. ln the art of treating` liquid materials, the improvement which consists in concentrating the liquid material by flowing the same by gravity and in the form of a film into contact with a succession of inclined surfaces over which the gravity flow of the liquid material is tranquilized, and concurrently with the gravity flow of such film heating the liquid material and exposing the same to the action of a drying atmosphere.

2. In the art of treating milk, the improvement which consists in concentrating` and pasteurizing the milk by diffusing' and flowing; the same by gravity and in the form of a film into contact with a succession of inclined surfaces over which the gravity flow of the milk is tranquilized, and concurrently with the flow heating,y the milk to a temperature for e'ffecting` the pasteuriz/.ation and exposing the heated milk film to the action of a drying atmosphere circulatml into contact with themilk film.

3. ln the art of trc-atinp` milk, the process which consists in lifl`usingI milk in the form of a film and flowing the same into contact with a succession of inclined surf-aces, heating the milk film to a temperature for effecting` pasteurization and coneurrently with the .fiow of the milk in a film-like condition exposing the film to the action of a drying` atmosphere whereby the milk is concentrated by the evaporation-of the. aqueous constituent and such concentration and pasteurization are performed sin'uiltaneously.

li. In the art of treating milk, the process which consists in flowing milk by gravity in the form of a film int-o contactyith a succession of inclined surf-aces over which the flow of such milk film is tranrpiiliized, heating the milk during the period of its flow to a temperature which pasteurizes the same, and exposing' said. heater film while it is in motion to a drying` atmosphere for evaporatng the aqueous constituent of the milk, whereby the milk is concurrcntly pasteurized and concentrated.

5. In the art of treating` milk, the process which consists in diffusing and fiowing milk in the form of a film over surfaces the angles of inclination of which increase from the point of feed to the point of exit, heating,` the milk film duringI the period of its flow to a temperai'ure which effects pasteurizcation of the milk, and exposing the milk film while in motion orer said sui-faces to a drying atmosphere for evaporating the aqueous content of the milk and concentrating the latter while undergoing pastcurization.

In testimony whercof I hare signed my name hereto this 11th day of October, 19120.

GORDON DON HARRY.

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